Jack



May 18, 1937. w. J. FIEDLER JACK Filed Oct. 25. 1936 3 Sheets-Sheet l W. J. FIEDLER May 18, 1937.

' JACK I Filed Oct. 25, 1936 I5 Sheets-Sheet 2 Q I RN nwN L 1T NW IIIIIC ,May 18, 1937. w J. FIEDLER JACK Filed Oct. 25, 1936 5 Sheets$heet 5 Patented May 18.1937

JACK

William J. Fledler, Mitchell, s. one, asslgnor of one-half to Adolph Schelske Application October 23, 1936, Serial No. 107,291 6 Claims. (Cl. 254-4 This invention relates to a floor jack of the type adaptedv for lifting an end of an automobile or other motor vehicle. The jack may also be effectively used in lifting other objects,fhow-,

ever.

An object of the invention is to provide a Jack by which a loadflmay be lifted with ease.

through any portion of its lifting range, and .which is provided with auxiliary lifting mechanism to facilitate operation through the lower portion of the lifting range.

Another object is to provide a jack in which mechanical advantage is gained by utilizing the reaction of a lifting cylinder.

16 A further object is to provide a jack of simple sturdy construction, and which is convenient to operate. Other objects and advantages will appear as the specification proceeds.

A preferred embodiment of my invention is shown in the accompanying drawings in which- -Fig. 1 is a view in side elevation of the jack -showing the lifting member in lower or closed position; Fig. 2, a sectional view taken as indicated at line 2-2 of Fig. 3, showing the lifting member in lower position and the handle broken away; Fig. 3, a plan view of the jack, the handle being broken away and a portion of the lifting member broken away to expose the lifting cylinder; Fig. 4, a sectional view similar to Fig. 2,

but showing the lifting member in raised position; Fig. 5, a sectional view taken as indicated at line 55 of Fig. 4; Fig. 6, a fragmentary view showing the pump and valve arrangement; and Fig. 7, a detail view of the handle connection.

As illustrated, A designates a frame; B, a liftting -member; .0, cam members; and D, mechanism for actuating the cam members and the lifting member.

The frame A may be of any, well known construction suitable for this type of device. As illustrated, it includes a channel iron l0 which is equipped at'the frontwith the brackets l I and I2 for holding the casters l3 and M. In the rear it contains an axle ii to which is attached 5 the rear wheels i6 and I1. Over axle I5 is 55 head l9 which is cupped to engage an automobile axle or other object to be raised. The link 26 connects the edge of head l9 with the frame at a point just forward of pin it, and serves to keep head l9 always in upright position. Suitable rollers 48 are mounted on the inside of member 5 B and are adaptedto engage with the cam members later to be described.

The cam members C, of the general shape as illustrated, are pivotally mounted in frame A by the pin 2| which extends transversely through 10 the sides of channel l0 and through the lower rear portion of members '0. The upper surfaces of the cam members are concave near the rear. portion as indicated at 22. Their surfaces at a 1 more forward portion, however, are convex as '15 indicated at 23.

The means for actuating the lifting member and the cam members comprises a cylinder 24 which at its rearward end is mounted between members C on pin 25 which extends through the 20 upper rear portion of members C. Within cylinder 24 is the plunger head 25 to which is attached the hollow plunger rod 26. Fittings 21 are screwed into cylinder 24 and about rod 2 for preventing the escape of oil from-the cyl- 25 inder. At its forward end rod 26 is pivotally secured to the lifting member B by the pin 28. The passage 29 within rod 26 is open to the interior of cylinder 24, and at the forward portion of plunger 26 a hollow screw 39 connects this pas- 30 sage with the exterior of the plunger. A flexible tube 3| connects hollow screw 36 with oil pumping mechanism shown more clearly in For actuating the oil pump 32, I provide the 35 handle 33 which is secured to shaft 34 rotatably spring 4| on piston 38 serves to withdraw the piston after the stroke is completed.

Pump 32 operates to force oil fromreservoir 42 through suitable passages including valves such as 42 and 44 to passage 29. Another pipe 45 containing release valve 46 connects the pas-'- 5 sageway 29 ,with theoili reservoir. Suitable means for controlling release valve'46 suchas rod 41 extending to the end of handle is provided.

Aflexibie tube 5| connects the rear portion of g 2 the cylinder with tank 42. The purpose of this tube' is to relieve the pressure behind plunger 26 when the plunger approaches maximum rear- As shown in Figs. 1 and 2, when the Jack is in closed position the plunger 26 is well back in l cylinder 24, and lifting member 13 and cammembers C are in lower position. when itis desired to use the jack to raise some object, the

operation is as follows: v

By either moving handle 83 up and down, or

15 simply operating treadle 36 by foot, the. oil pump 32 is actuated.- This forces oil from the reservoir 42 through valves 43 and 44, and through tube ii and passage 29 into cylinder 24. The pressure of oil within cylinder 24 causes the cylinder to be urged rearwardly and plunger 26 urged forwardly, the effect being to expand the distance between pins l8 and 25. But, as clearly shown in Fig. 2, when the jack is closed the pin I8 is almost aligned with plunger 26, and though plung- 25 er 26 is urged forwardly it will have only small purchase for raising lifting member B. However,

as cylinder 24 is urged rearwardly with equal' force, the cam members C will be turned about pivot pin 2| and their surfaces urged upwardly against rollers 48. Backward movement of the cylinder will then cause lifting member B to be raised, the rollers 48 rolling along the cam surfaces of member B.

When the cam members have been so turned -3 that the rollers 48 approach the ends of members C, the lifting member will have been raised to a position where the plunger has gained sumcient purchase to raise the lifting member to still high"- er positions such as shown in Fig. 4. The stop 40 supports cylinder 24 ,when the function of the cam me rs is completed.

From t e above it maybe seen that the cylinder and plunger are effective for raising the lifting member in two ways; first, by turning the 45 cam members about their pivots to raise the lifting member, and secondly, through direct connection of the plunger with the lifting member. At the lower positions of the jack the lift comes principally through the cam members and at 5 higher positions the lift comes principally through the plunger connection.

When it is desired to release the Jack to let down its load, the operator may turn rod 41 to release valve 46 and allow oil to flow back into the reservoir, the decrease in pressure then allowing the lifting member to be lowered to closed position.

This jack has an important advantage in that it can be placed under low objects and is capable m of raising heavy loads at relatively low positions.

In common jacks of this type now in use a common objection is that they do not have sufficient lifting leverage or purchase either at the lower or higher positions of the lifting member.

65 By using means for effecting the double purchase I have eliminated such an objection. Another important advantage is gained'by the use of s single cylinder for producing both ofthe lifting forces as above set forth.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, but the appended claims-should be construed as broadly as'permissible, in view of the prior art.

-I claim? d a 1. A lack comprising a frame, a lifting member pivotally mounted on said frame, a cam member mounted on said frame and having its cam surface in contact with said lifting member, and a cylinder attached to said cam member and arranged to rock said can member to raise said lifting member.

2. A jack comprising a frame, a lifting member pivotally mounted on said frame, a cam member mounted in said frame and having its cam surface in contact with said lifting member, a cylinder attached to said cam' member, and a plunger associated with said cylinder and havingv its one end pivotally attached to said lifting member.

3. A jack comprising a frame, a lifting member attached to said frame, a cam member -pivotally attached to said frame and having its cam surface in contact with said lifting member, and expansive means for rocking said cam member about its pivot, said means being connected to said lifting member and adapted to urge said lifting member at' the point of connection.

4. A Jack comprising a frame, a lifting member attached to said frame, a pair of cam mem bers pivotally attached to said frame and having their cam surfaces in contact with said lifting member, and expansive means connected at one end to said cam members and at its-other end to said lifting member, said means being so arranged that when expanded its one end urges said lifting member upward and its other end moves said cam members about their pivots to urge said lifting member upward.

5. A lack comprising a frame, a lifting member attached to said frame, a cam member pivotally secured in said frame and having its cam surface in contact with said lifting member, and expansive means in direct connection'with said lifting member, said means being also effective for rocking said cam member about its'pivot to raise said lifting member, said means being adapted to exert greater turning moment through said cam member when said lifting member is in a lower position and to exert a greater turning moment through its direct connecton with said lifting member when said lifting member is at a higher position.

6. A jack comprising a frame, a lifting mem ber pivotally mounted on said frame, a cam member pivotally mounted on said frame, and in engagement with said lifting member, and means attached to said lifting member for rocking said cam member about its pivot to raise said lifting member.

WILLIAM J. FIEDLER. 

